[Study on therapeutic window of opportunity for Panax notoginseng saponins following focal cerebral ischemia/reperfusion injury in rats].

OBJECTIVE: To study the therapeutic window of opportunity for Panax notoginseng saponins (Pns) following focal cerebral ischemia/reperfusion injury in rats. METHODS: Focal cerebral ischemia (2 h)/reperfusion (24 h) model in male rats was induced by transient occlusion and middle cerebral artery (MCA) for 2 h and reperfusion for 24 h. Drugs were administered at 3 h, 4 h, 5 h and 6 h after the onset of ischemia respectively and neurological deficit score, infarct size and brain edema were examined. RESULTS: The administration of Pns at 3-4 h after onset of ischemia significantly reduced neurological deficit score, infarct size and brain edema. When administrating Pns at 5 h after onset of ischemia, the neuroprotection decreased. When administrating Pns at 6 h after onset of ischemia, there are not significant protective effects. CONCLUSION: The therapeutic window of opportunity for Pns following focal cerebral ischemia/reperfusion injury in rats is not more than 5 h after the onset of ischemia.